Electric motor having support surfaces for maintenance

Abstract

According to one embodiment, an electric motor includes a stator, a rotor, bearings and a rotor shaft, in a frame, supporting surfaces on the rotor, and a plurality of threaded holes in the frame, which are configured to receive bolts for pressing the support surfaces from outside.

What is claimed is: 
     
       1. An electric motor comprising:
 a stator; 
 a frame supporting the stator; 
 a bracket and an end plate configured to close respective ends of the frame; 
 a first bearing housing and a second bearing housing respectively retaining bearings, and respectively fixed to the bracket and the end plate from an outside; 
 a rotor shaft arranged inside the frame and rotatably supported by the bearings; 
 a rotor attached to the rotor shaft and opposing the stator; 
 a first supporting body and a second body attached to the rotor shaft at respective sides of the rotor and respectively including tapered supporting surfaces; and 
 a plurality of threaded holes for fixing formed respectively in the bracket and the end plate to oppose the supporting surfaces, and into which a supporting member for fixing the rotor that presses the tapered supporting surfaces are configured to be insertable from outside, 
 wherein the plurality of threaded holes are formed in a manner penetrating in a direction substantially perpendicular to the tapered supporting surface and extends into the frame towards the tapered supporting surface, and 
 the supporting member is inserted in the plurality of threaded holes for fixing and presses each of the tapered supporting surfaces. 
 
     
     
       2. An electric motor according to  claim 1 , wherein the rotor comprises a rotor core attached to the shaft, and rotor core holders attached to the rotor shaft at respective sides of the rotor core and respectively including the supporting surfaces. 
     
     
       3. The electric motor according to  claim 2 , wherein the supporting surfaces of the core holders comprise tapered surfaces positioned at least at parts on a circumference having the rotor shaft as a center, and the plurality of threaded holes are formed in the bracket and the end plate so as to align on circumferences having the rotor shaft as centers.